SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd780c94c40a2a5710c06de5a89f6500e404e183404f6265f73ae7b0226e9d1f4' 
  AND token = 'gTTu8sLCIVFrvha54XVTrtpxlnQxHGPl3EMB181LmeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}